这段代码产生了一个怪物，但没有敌人。 我希望产生一个敌人，为什么不呢？
#import "MyScene.h"
#import "GameOverScene.h"
static const uint32_t projectileCategory = 0x1 << 0;
static const uint32_t monsterCategory = 0x1 << 1;
static const uint32_t enemyCategory = 0x1 << 1;
// 1
@interface MyScene () <SKPhysicsContactDelegate>
@property (nonatomic) SKSpriteNode * player;
@property (nonatomic) NSTimeInterval lastSpawnTimeInterval;
@property (nonatomic) NSTimeInterval lastUpdateTimeInterval;
@property (nonatomic) int monstersDestroyed;
@property (nonatomic) int enemysDestroyed;
@end
static inline CGPoint rwAdd(CGPoint a, CGPoint b) {
return CGPointMake(a.x + b.x, a.y + b.y);
}
static inline CGPoint rwSub(CGPoint a, CGPoint b) {
return CGPointMake(a.x - b.x, a.y - b.y);
}
static inline CGPoint rwMult(CGPoint a, float b) {
return CGPointMake(a.x * b, a.y * b);
}
static inline float rwLength(CGPoint a) {
return sqrtf(a.x * a.x + a.y * a.y);
}
// Makes a vector have a length of 1
static inline CGPoint rwNormalize(CGPoint a) {
float length = rwLength(a);
return CGPointMake(a.x / length, a.y / length);
}
@implementation MyScene
-(id)initWithSize:(CGSize)size {
if (self = [super initWithSize:size]) {
// 2
NSLog(@"Size: %@", NSStringFromCGSize(size));
// 3
self.backgroundColor = [SKColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:1.0];
// 4
self.player = [SKSpriteNode spriteNodeWithImageNamed:@"player"];
self.player.position = CGPointMake(self.player.size.width/2, self.frame.size.height/2);
[self addChild:self.player];
self.physicsWorld.gravity = CGVectorMake(0,0);
self.physicsWorld.contactDelegate = self;
}
return self;
}
-(void)addMonster {
// Create sprite
SKSpriteNode * monster = [SKSpriteNode spriteNodeWithImageNamed:@"monster"];
monster.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:monster.size]; // 1
monster.physicsBody.dynamic = YES; // 2
monster.physicsBody.categoryBitMask = monsterCategory; // 3
monster.physicsBody.contactTestBitMask = projectileCategory; // 4
monster.physicsBody.collisionBitMask = 0; // 5
// Determine where to spawn the monster along the Y axis
int minY = monster.size.height / 2;
int maxY = self.frame.size.height - monster.size.height / 2;
int rangeY = maxY - minY;
int actualY = (arc4random() % rangeY) + minY;
// Create the monster slightly off-screen along the right edge,
// and along a random position along the Y axis as calculated above
monster.position = CGPointMake(self.frame.size.width + monster.size.width/2, actualY);
[self addChild:monster];
// Determine speed of the monster
int minDuration = 2.0;
int maxDuration = 4.0;
int rangeDuration = maxDuration - minDuration;
int actualDuration = (arc4random() % rangeDuration) + minDuration;
// Create the actions
SKAction * actionMove = [SKAction moveTo:CGPointMake(-monster.size.width/2, actualY) duration:actualDuration];
SKAction * actionMoveDone = [SKAction removeFromParent];
SKAction * loseAction = [SKAction runBlock:^{
SKTransition *reveal = [SKTransition flipHorizontalWithDuration:0.5];
SKScene * gameOverScene = [[GameOverScene alloc] initWithSize:self.size won:NO];
[self.view presentScene:gameOverScene transition: reveal];
}];
[monster runAction:[SKAction sequence:@[actionMove, loseAction, actionMoveDone]]];
}
- (void)updateWithTimeSinceLastUpdate:(CFTimeInterval)timeSinceLast {
self.lastSpawnTimeInterval += timeSinceLast;
if (self.lastSpawnTimeInterval > 1) {
self.lastSpawnTimeInterval = 0;
[self addMonster];
}
}
- (void)update:(NSTimeInterval)currentTime {
// Handle time delta.
// If we drop below 60fps, we still want everything to move the same distance.
CFTimeInterval timeSinceLast = currentTime - self.lastUpdateTimeInterval;
self.lastUpdateTimeInterval = currentTime;
if (timeSinceLast > 1) { // more than a second since last update
timeSinceLast = 1.0 / 60.0;
self.lastUpdateTimeInterval = currentTime;
}
[self updateWithTimeSinceLastUpdate:timeSinceLast];
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
[self runAction:[SKAction playSoundFileNamed:@"pew-pew-lei.caf" waitForCompletion:NO]];
// 1 - Choose one of the touches to work with
UITouch * touch = [touches anyObject];
CGPoint location = [touch locationInNode:self];
// 2 - Set up initial location of projectile
SKSpriteNode * projectile = [SKSpriteNode spriteNodeWithImageNamed:@"projectile"];
projectile.position = self.player.position;
projectile.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:projectile.size.width/2];
projectile.physicsBody.dynamic = YES;
projectile.physicsBody.categoryBitMask = projectileCategory;
projectile.physicsBody.contactTestBitMask = monsterCategory;
projectile.physicsBody.contactTestBitMask = enemyCategory;
projectile.physicsBody.collisionBitMask = 0;
projectile.physicsBody.usesPreciseCollisionDetection = YES;
// 3- Determine offset of location to projectile
CGPoint offset = rwSub(location, projectile.position);
// 4 - Bail out if you are shooting down or backwards
if (offset.x <= 0) return;
// 5 - OK to add now - we've double checked position
[self addChild:projectile];
// 6 - Get the direction of where to shoot
CGPoint direction = rwNormalize(offset);
// 7 - Make it shoot far enough to be guaranteed off screen
CGPoint shootAmount = rwMult(direction, 1000);
// 8 - Add the shoot amount to the current position
CGPoint realDest = rwAdd(shootAmount, projectile.position);
// 9 - Create the actions
float velocity = 480.0/1.0;
float realMoveDuration = self.size.width / velocity;
SKAction * actionMove = [SKAction moveTo:realDest duration:realMoveDuration];
SKAction * actionMoveDone = [SKAction removeFromParent];
[projectile runAction:[SKAction sequence:@[actionMove, actionMoveDone]]];
}
- (void)projectile:(SKSpriteNode *)projectile didCollideWithMonster:(SKSpriteNode *)monster {
NSLog(@"Hit");
[projectile removeFromParent];
[monster removeFromParent];
self.monstersDestroyed++;
if (self.monstersDestroyed > 80) {
SKTransition *reveal = [SKTransition flipHorizontalWithDuration:0.5];
SKScene * gameOverScene = [[GameOverScene alloc] initWithSize:self.size won:YES];
[self.view presentScene:gameOverScene transition: reveal];
}
}
- (void)didBeginContact:(SKPhysicsContact *)contact
{
// 1
SKPhysicsBody *firstBody, *secondBody, *thirdBody;
if (contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask)
{
firstBody = contact.bodyA;
secondBody = contact.bodyB;
thirdBody = contact.bodyB;
}
else
{
firstBody = contact.bodyB;
secondBody = contact.bodyA;
thirdBody = contact.bodyA;
}
// 2
if ((firstBody.categoryBitMask & projectileCategory) != 0 &&
(secondBody.categoryBitMask & enemyCategory) != 0 &&
(thirdBody.categoryBitMask & monsterCategory) != 0)
{
[self projectile:(SKSpriteNode *) firstBody.node didCollideWithMonster:(SKSpriteNode *) secondBody.node];
[self projectile:(SKSpriteNode *) firstBody.node didCollideWithEnemy: (SKSpriteNode *) secondBody.node];
}
}
- (void)addEnemy {
// Create sprite
SKSpriteNode * enemy = [SKSpriteNode spriteNodeWithImageNamed:@"enemy"];
enemy.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:enemy.size]; // 1
enemy.physicsBody.dynamic = YES; // 2
enemy.physicsBody.categoryBitMask = enemyCategory; // 3
enemy.physicsBody.contactTestBitMask = projectileCategory; // 4
enemy.physicsBody.collisionBitMask = 0; // 5
// Determine where to spawn the monster along the Y axis
int minY = enemy.size.height / 2;
int maxY = self.frame.size.height - enemy.size.height / 2;
int rangeY = maxY - minY;
int actualY = (arc4random() % rangeY) + minY;
// Create the monster slightly off-screen along the right edge,
// and along a random position along the Y axis as calculated above
enemy.position = CGPointMake(self.frame.size.width + enemy.size.width/2, actualY);
[self addChild:enemy];
// Determine speed of the monster
int minDuration = 1.0;
int maxDuration = 6.0;
int rangeDuration = maxDuration - minDuration;
int actualDuration = (arc4random() % rangeDuration) + minDuration;
// Create the actions
SKAction * actionMove = [SKAction moveTo:CGPointMake(-enemy.size.width/2, actualY) duration:actualDuration];
SKAction * actionMoveDone = [SKAction removeFromParent];
SKAction * loseAction = [SKAction runBlock:^{
SKTransition *reveal = [SKTransition flipHorizontalWithDuration:0.5];
SKScene * gameOverScene = [[GameOverScene alloc] initWithSize:self.size won:NO];
[self.view presentScene:gameOverScene transition: reveal];
}];
[enemy runAction:[SKAction sequence:@[actionMove, loseAction, actionMoveDone]]];
}
- (void)projectile:(SKSpriteNode *)projectile didCollideWithEnemy:(SKSpriteNode *)enemy {
NSLog(@"Hit");
[projectile removeFromParent];
[enemy removeFromParent];
self.enemysDestroyed++;
if (self.enemysDestroyed > 80) {
SKTransition *reveal = [SKTransition flipHorizontalWithDuration:0.5];
SKScene * gameOverScene = [[GameOverScene alloc] initWithSize:self.size won:YES];
[self.view presentScene:gameOverScene transition: reveal];
}
}
@end
答案 0 :(得分：3)
我不确定你是否意识到这一点，但你实际上从未打电话给addEnemy。仔细查看代码。您会收到addMonster的来电，但永远不会addEnemy。实现该方法是一回事 - 无需调用方法，内部的任何内容都将无法运行。